Abstract Introduction Radiation oncology is a pivotal modality in the treatment of hematologic malignancies. To enable state-of-the-art patient care, structured education during residency is essential. However, given the lack of detailed data, the scope of educational opportunities available to trainees remains elusive. This prompted our group to perform a national survey amongst radiation oncology residents in Germany assessing the status quo of competences in the treatment of lymphoma and leukemia patients. Furthermore, areas of potential improvement were identified to further the goal of competence-based education for residents. Methods A survey-based analysis was conducted to assess the knowledge and competence of radiation oncology residents in Germany regarding hematological malignancies. A decisive questionnaire covering demographics, self-assessment of competences, and areas for improvement was developed in adaption of a survey by the Association of Residents in Radiation Oncology and distributed amongst 1439 members of the German Society of Radiation Oncology. Responses were collected anonymously via an online survey tool and analyzed using descriptive statistics and chi-square tests. Results A total of 59 complete and 22 partial responses were collected, yielding a 5.6% response rate. Participants’ competence varied, with notable experience gaps in pediatric cases, proton therapy, and large-field techniques like total-skin irradiation or pediatric total body irradiation. While participants felt confident in treatment planning and patient counseling, they showed deficiencies in the definition of the planning target volume for modern involved site radiotherapy. Resources for education included national and international guidelines, scientific reviews, and textbooks. Board-certified radiation oncologists and physicians from specialized lymphoma centers demonstrated higher overall competence levels. Conclusion This survey highlights the diversity of resident education regarding hematological malignancies in German radiation oncology programs. Knowledge gaps exist in key areas, including pediatric cases and specialized techniques. Competence-based education, interactive teaching formats, and rotations to specialized centers are potential strategies to address these gaps. The study contributes to the understanding of the federal educational landscape, underscoring the need for standardized and comprehensive training to ensure optimal patient care in hematological malignancies within the context of radiation oncology. Further research and collaborations are warranted to enhance training and expertise in this critical domain.